中文摘要：

在实验室条件下观测了青藏高原东部高寒草甸54种禾本科植物的种子萌发特点.结果发现：在54种植物中,有43种植物种子萌发率都达到了50%,其中萌发率80%以上的物种有26种,60%～80%的有11种,40%～60%的有8种,20%～40%的有5种,小于20%的有4种;萌发开始时间为3～5 d的植物有14种,6～8 d的植物有29种,9～10 d的植物有10种,大于10 d的有1种;萌发持续时间为1～7 d的植物有16种,8～14 d的植物有28种,15～21 d的有10种;达50%萌发率的时间为1～7 d的植物有11种,8～14 d的植物有27种,大于14 d的植物有5种,萌发率一直没达到50%的植物有11种.这些植物显示了4种萌发类型：爆发型、过渡型、缓萌型（萌发率大于50%的物种）和低萌型（萌发率小于50%的物种）.

英文摘要：

Background and Aims The study area is located on the eastern Qinghai-Tibetan Plateau （ 101° - 103° E, 34° - 35°70＇ N）. The altitude ranges from 2 900 m to 4 000 m, and the climate is cold and humid with an annual rainfall of 450 - 780 mm, which is mainly distributed in July, August and September. Mean annual air temperature is 1.8 ℃ with - 10.7 ℃ in January and 11.7 ℃ in July, and average annual frost days are no less than 270 d. The grassland types include mainly alpine meadow （59.32%）, brushy meadow （33.39%）, woodland meadow （0.32%）, saline meadow （0.15%）, swampy meadow （5.61%） and upland grass （1.21 % ）. The vegetation belongs to typical alpine meadows, and the species composition of the plant community is dominated by many monocotyledons and various dicotyledons. The capacity of seed germination and seedling establishment determines partially the regeneration of plant communities of the grassland. However, there is few germination data. Accordingly, we have undertaken a major study of the gramineous species of the alpine meadow. A comparison of the germination biology of many species will provide an ecological context for subsequent studies of fidd distribution. Methods Seeds were collected from as many sources as possible to get an adequate representation of the whole community from July to October in 2003. Enveloped seeds were spread on tables at room temperatures （about 15 ℃）until dried and threshed by hand through screens. The experiment of germination started on March 3, 2004. For each species 50 seeds were placed in Petri-dishes on filter paper moistened with distilled water in a growth chamber with a 12-h day at 25 ℃ and a 12-h night at 5 ℃. This temperature regime has relevance to field conditions： it approximates the mean daily maximum and minimum temperature in 5 cm deep soil from May to August. The percentage of seeds germinated was recorded every day. Newly emerged seedlings were removed from the Petri-dishes and seeds were regularly watered wi